People cautioned a vacationer to 'keep going' after noticing 'beautiful tiny pineapples' clinging to cruise ship doors.

In most cases, pineapple emblems and ornaments are just aesthetic homage to the tropical fruit, which is native to West Africa and Latin America.

In popular culture, you may recall Nickelodeon's SpongeBob SquarePants, in which the titular cartoon character lives in a pineapple under the sea. It's a fun and unique habitat for the beloved sea sponge.

However, when it comes to adult cruises, the herbaceous perennial has a very other meaning, as one seemingly innocent TikTok user learned.

Dominique (@blogionistatravels) used social media to capture her maiden cruise trip.

She was eager and interested, revealing every element of her journey.

In one of her films, she mentioned how she noticed some unique designs on several cabin doors.

In the 15-second video, which has had 21 million views since its release in September 2022, the travel blogger pans down a corridor lined with dwelling units.

Many of the doors looked to have various pineapple stickers slapped on.

In overlay text, Dominique wrote: "When you're on your first cruise and you see that everyone has these little cute pineapples on their door."

After seeing the film, people rushed to the comments area to express their opinions on the pineapple stickers.

One TikTok user wrote: "The welcome one with the butterfly makes me think it's a sweet old lady that thinks people just decorate with pineapples on cruises & want to decorate."

This statement emphasized the innocence that some people may still connect with the pineapple sign.

A second user typed: "Still waiting on name of cruise… for a friend of course," hinting at a deeper curiosity about the cruise's nature.

Another viewer said, "It could just be the cruise put them there. It's the international hospitality symbol," trying to rationalize the decorations as merely friendly gestures.

However, the remarks did not end there. Someone another commented, "Ooop, don't go in unless you want to mix things up, if you know what I mean," revealing the secret meaning.

Another user contributed a personal anecdote: "I remember the time I decorated our tent site in pineapples and learned at 2 am what message I was sending. Mortified! I stick to watermelons now!!"

This amusing yet insightful reply highlighted the unexpected meanings of certain symbols.

Finally, someone said, "Baby, just keep walking," implying that not every door is intended to be knocked on.

Typically, these subtle themes are arranged upside down to serve as a secret code for swinging, swinger parties, and wife swapping.

Interestingly, these aren't the only indicators that swingers—people who participate in group sex or switch sexual partners—use to identify one another.

Many swingers on vacation wear black rings, and married couples may choose to wear their wedding bands on their right hand rather than the conventional left.

If you don't mind being open about your sexual inclinations, you may book an adult-only swingers cruise.